Your machine has a 15 AMP charging system, so at high speed, you should have sufficient current. Headlights & fuel solenoid will use around 5-6 AMPs and PTO probably around 3-4? HOWEVER- IF the battery is low in charge, it may "suck" a higher than normal amount and thus drop the voltage to the point that the PTO disengages. I would start off by fully charging the battery and see if that resolves the problem (at least temporarily). IF the battery is 2 or more years old, I'd definitely get it load tested. As a matter of course, you should ensure that the connections to the PTO SWITCH and PTO are good. You should unplug/plug a couple times to "wipe off" any "crud".

Disassemble the carburetor and give it a judicious cleanout using spray carb cleaner and compressed air. You might also want to post the engine model number and the Craftsman technical model number (9 digit number under the seat). Of course, if this machine has a fuel cutoff solenoid valve on the carburetor, that might not be working and could cause the same symptom you are reporting. Take your can of "starting fluid" and throw it in the trash. You should not use it on these light duty engines. Spray carburetor cleaner is much safer (for the engine) to use as an alternate fuel by spraying into the carb throat when diagnosing fuel problems.

Everything I see in the wiring diagram says you have a defective, or maladjusted, or loose clutch/brake switch. And it corresponds to what you describe. By the diagram in the owner's manual, you should be able to vacate the seat while the engine is running if you lock the brake pedal down. Locking down the brake/clutch pedal causes the switch to OPEN the "magneto kill circuit" and PREVENTS the the magneto circuit (which also is the tachometer signal circuit) from being grounded by the Operator Presence Relay when the seat is vacated. If it was a problem in the seat switch, the engine would have quit while you were driving the tractor, or, it never would have started in the first place. Check the mounting of the brake/clutch switch and make certain the switch is secure and that the plunger is getting the correct amount of travel when the pedal is locked down. Essentially, your ignition system is being "shut off" chaotically. The pops and "backfires" result from unburned gasoline being expelled from the combustion chamber into the muffler when the ignition is not sparking, and then that volume of fuel in the muffler gets "lit up" when the sparking resumes. The same thing happens when you "rock the seat" (as you already noticed).

Mownie: I received and installed my new regulator today. This is what I found in the following sequence: * 12.86 V DC prior to starting * 13.86 V DC after starting at full throttle * 14.13 V DC at full throttle and with the mower deck engaged and after running the mower deck for 15 minutes * 13.97 V DC at full throttle with the mower deck NOT engaged, but after running the mower deck for 15 minutes It appears as if you have guided me in the right direction and allowed me to fix my charging problem. I wish to thank you again for all of your help and diligence. I will continue to monitor my tractor so that I can confirm my gremlins have checked out. MM